Telephone system



May 21, 1940. w. w. CARPENTER Er AL 2,201,573

TELEPHONE SYSTEM Filed NOV. 16, 1938 4 Sheets-Sheet 1 FS VS n@ Tin NS ATTORNEY 4 Sheets-Sheet 2 TELEPHONE SYSTEM Filed Nov. 16, 1938 w. w. CARPENTER Er A1.

[Nl/ENTORS. WW CARPENTER By L.E. K/TT-REDGE ATTORNEY llll-.IIIIIII May 2l, 1940.

FIGB

W. W. CARPENTER ET AL TELEPHONE SYSTEM Filed Nov. 16, 1938 4 Sheets-Sheet 3 mffgna UH #H A W WCARPE/v TER NVENQOfS' .E. K/TTREDGE A TTORNEV May 21, 1940 w. w. CARPENTER Er AL 2,201,573

TELEPHONE SYSTEM Filed Nov. 16, 1938 4 Sheets-Sheet 4 li--lll IHI /Nl/ENTORS:

ATTORNEY Patented May 21, 1940 2,201,573

TELEPHONE SYSTEM Warren W. Carpenter, Garden City, and Linus E. Klttredge, Port Washington, N. Y., assignors to Bell Telephone Laboratories, Incorporated. New York, N. Y., a corporation of New York Application November 16, 1938, Serial No. 240,698

s claims. (c1. 17a-1s) prior art, a certain degree of exibility was obnumber of switches included in alevel and; there- 5 tained by dividing the subscribers lines into large fore, the number of lines in that level being degroups, in accordance with the switching equiptermned by traic conditions. y ment by which the lines were served, within In the establishment of terminating connecwhich the lines might be transferred freely by tions, a terminating sender and terminating 10 change of cross-connections without change in marker are employed, the sender receiving the number and between which the lines might be line designation from the originatingequipment interchanged without change of number proand transferring it to the marker. From this viding a sufficient number of lines were transregistration the marker rst selects a set of terferred at the same time. s minals representing a group of twenty line num- 15 In accordance with the present invention, combers withinwhich the wanted line number lies. plete independence of the line number and the By this selection the marker determines the line location in the switching equipment is atnumber group frame on which the terminals of tained. To this end there is provided a set of the wanted number are mounted and by means of terminals for each line enteringvthe oiiice, sets of the number group connector selects a number 20 incoming terminals for the primary line switches frame land operates a hundred-block relayl and a and a set of terminals for each line number to twenty-block relay on that frame. With the be used in the oflice, and means are provided forv twentyfblock Arelay operated, a set ,of three cirindividualizing one of the sets of number termicuits for eachof the twenty numbers is extended 5 nals to one of said line terminals and. switch infrom the marker to twenty sets of threetermi- 25 coming terminals. With means fOI Varying Such nals each on the number frame, individual to the individualization. That is, the number assigned twenty numbers included in the twenty block. to a line may be altered Without altering the Forv the establishment of a connection to the connection between the line terminals and switch Wanted une it is necessary that thelmarker know 30.termna1s 0r the line may be connected t0 a dfthe line choice within which the line is located, 30 fert Set 0f Switch terminals without altering theframe within the choice and the1eve1on the the number assigned to it. frame., It is also necessary to know whether the The invention will be more Clearly understood wanted line is yan individual line, a party line or v'from a consideration of the following description y one of a, group of lines leading to a private Vbranch in connection with the drawings in which: exchange and, if a partyA line, whether it isa tip 35 Fig. 1 SHOWS the equipment incoming t0 an or ring party. Furthermore, the-marker must Office and a number giOliD frame and conneCtOl; know whether the wanted lineA is busy or idle. Fig. 2 shows parts of two line choices; Therefore, there is provided'on the number frame Fig. 3 shows the registering equipment of the a block ofv control terminal strips representing 40 marker; and f line switch levels. Forty terminalstrips are pro- 40 Fig. 4 shows additional equipment in the vided, one for each level of the fourV frames in marker. any one choice. `A second block of` terminals 'I'he present disclosure is a skeletonized showcombines the identification of the line choice'and ing of the terminating equipment of an office. A the class of the line, there being ten sets of ,three f more complete showing of the marker for conterminal strips each,l to carel for a, maximum of 5 trolling such equipment is to be found in the coten ,line choices. One strip of each set'reprepending application of J. W. Dehn et al., Serial sents an individual line, the lring party line or No. 240,718, filed concurrently herewith. the last line of a private branch exchange group y In the cross-bar system, each switch unit comsince all of these lines are handledl in the same prises one hundred contact elements which promanner. The second strip of eachset represents' 50 vide junctionsV between ten incoming elements tip party service and the third strip of each-set and ten outgoing elements. The switches which represents a first or intermediate line of a private serve the subscribers lines are known as primary branch exchange trunk group. These stripsare line switches and one to seven of these switches connected through the number group connector are arranged in a horizontal group known as a to equipment in the marker which controls the n This invention relates to telephone systems and has for its object increased flexibility in the determination of numbers and locations for subscribers lines.

As disclosed in the cross-bar system of the level, ten levels of which are arranged vertically to constitute a frame, four frames comprising a line choice. One subscribers line is connected to each of the incoming elements and, therefore, a choice may serve from 400 to 2800 lines,'the

establishment oi a connection in accordance with infomation received therefrom.

When both the location of a line and its class of service is determined and a number is assigned thereto, two of the number terminals are crossconnected to the control terminal strips in accordance therewith. The third number terminal is connected directly to the winding of the line hold magnet and, therefore, to the sleeve of the line for determining its busy or idle condition.

Referring more speciilcally to the drawings, a call originated by a subscriber at substation |00 is extended by equipment, not shown, to an incoming junctor 0| which connects with an idle terminating sender |03 through a terminating sender link |02. The number of the wanted subscriber is then recorded on the terminating sender |03 which operates terminating marker connector |00 to summon a terminating marker.

When the sender and marker have been connected, the recorded designation is transferred to the marker and recorded on a set of registers represented by thousands relay 300, hundreds relay 30|, tens relay 302 and units relay 303. The himdreds relay 30| indicates whether the hundreds digit is greater or less than 5 by operating relay 305 i'or digits greater than 5 and indicates the position of the digit in either series by operating one of iive relays. such as relay 300. The thousands relay 300 marks one of ten conductors, such as conductor 300, which is extended to relay 301 or 300, according as relay 305 is or is not operated. Therefore, the joint operation of the thousands and hundreds register identiiies a group of 500 lines by operating one of a set of twenty relays, such as relays 301 and 300.

Theftens register represented by relay 302 discriminates between even and lodcl digits by operating relay 3|0 for odd digits and identifies blocks of twenty numbers by operating one of a set of ve relays, such as relay 300, which in turn operaies relay 3| i. The units register relay 303 grounds one of ten conductors, which are extended to twenty conductors, according to the operated or non-operated condition of relay 3|0.

Ihe joint operation of relay 300. and relay 301 or 300 selects a number group frame by completing a circuit i'or a marker preference relay, such as relay |00 or |00. In each number group connector there is a marker preference relay for each marker and these preference relays are arranged in a chain so that only one marker can attach itself to a-number group frame at a time. Assuming that the wanted number terminals are on number group frame |01, preference relay |00 is operated as`soon as the frame is idle, operating a multicontact relay |00 which closes the necessary circuits between the marker and the number frame. With relay |00 operated, the hundred-block relay |00 is operated under the control of relays 300 and 300, there being one relay |00 for each hundred numbers included in the number group. With relay |00 operated, twenty-block relay |0 is operated under the control of relays 3|| and I 00, there being one such relay for each twenty numbers on the number group frame.

With'relays |00, |09 and 0 operated, twenty sets of three terminals each on the number frame |01, such assets I|| to ||3 and ||0 to iii, are marked by connecting them to equipment in the marker. For example, terminal is connected over i'ront contacts of relays ||0 and. |00 to the winding of the busy test relay 3|2, while terminal |0 is similarly connected to the winding of relay 3|3. The corresponding terminals on the other eighteen sets are also connected to intermediate relays in the set of twenty busy test relays. Terminals ||2 and ||5 are connected to armatures of selecting relays 3 0 and 3|5, respectively, with the corresponding terminals of the remaining sets connected to armatures of intermediate relays oi this group. Terminals ||3 and ||0 are connected over back contacts of relays 3|0 and 3|! to the windings of relays 3|0 and 3|1 which become effective only in the case of terminal hunting groups.

As indicated above, in order to connect with a wanted line it is necessary to select the choice, frame and level on which the line is located and also to determine the class of service to which the line is entitled. Therefore, there is provided in the marker line choice relays 000, 00|, etc., there being one for each lchoice. Since each choice includes tour frames with ten levels on each frame, a set of twenty double wound relays 002 to 005 is provided. Each pair of relays 002 and 003 or 000 and 005 represents one of the ten levels and each relay represents a pair of frames, the two windings of each relay distinguishing between the frames of the pair. In order to differ- I entiatebetw'een the three types of service, the

line choice relays 000, 00|, etc., have three windings and are energized over the dinerent windings in accordance with the type of line. Therefore, there is a maximum of thirty conductors leading from the line choice relays and a maximum of forty conductors outgoing from the frame and level relays. 'I'hese conductors are extended in multiple to all of the number frame connector relays, such as relay |00 and |3|, and over contacts of these relays to sets of terminal strips on the number group frame. The operating conductors 000, 001 and 000 for relay 000 extend,

to terminal strips I|1, ||0 and ||0. it being assumed that the terminal strip is rendered continuous across the frame by connections at the back. Similarly. the operating conductors 000 to 0|2 for the frame level relays 002 and 003 are connected over contacts of relay |00 to terminal strips to |23.

'I'he subscriber's line 200, when it enters the omce. is connected toa distributing frame 20| from which the line is extended to one of the primary line switches 202 in accordance with trame requirements. The line itself is connected to the line terminals 203 and 200, while individual to the line terminals 203 and 200 are the sleeve or busy terminal 200 and the message register terminal 200.

At the number group frame, assuming that the set of number terminals III, ||2 and ||3 represent the number assigned to line 200, terminal will be cross-connected over jumper |20 to terminal 205 individual to the position in the primary switch 202 assigned to line 200. According to the present disclosure, line 200 appears on the No. 0 level of the No. 0' frame in the No. 0 choice and is an individual message rate line. 'I'herefore,'termina1 I2 is connected over jumper |25 to strip |20 and terminal ||3 is connected over jumper |20 to strip ||1.

When the twenty-block relay 0 operates as above described, the sleeve test circuit for line 200 extends from battery through the winding of relay 3|2, back contact of relay 3|0, over front contacts of relays |00 and l0, terminal III, jumper |20. to the sleeve terminal 200 individual to the line. If the line is busy, relay 3|2 operates from the busy ground on the sleeve oi' the line.

At the same time. batterythr'ough the Vwinding of relay 3I0V is connected over the back contact of relay 3I4, over contacts of relays |00 and IIO to terminal IIS. jumper |20, strip II1, conductor 400, left windingof the No. line choice relay 400 to battery. Therefore, relay SII does not operate. After an interval to permit the busy test relays 3I2,-3I3, etc. to operate, ground is connected under they control of the units register to conductor 3|0, thereby operating relay 3I4, provided relay 3I2 is not operated. With relay 0I'4 operated,vground is connected to conductors 3|!v and 320. Conductor 020 extends to terminal III, over jumper |26 to strip II'I, conductor 400, left winding of relay 400 and battery. The opera tion of relay 400 in this circuit identies the No. 0 line choice. I ground to the winding of relay4l3`to `indicate that the wanted line is to be handled as an individual line. Conductor 3|! extends to terminal II2, over jumper |25 to strip |20. conductor 400. left winding of relay 402 and battery. Relay 402 in operating identifies the No'. 0 levelv and extends its operating ground over its inner left contact to the winding of relay 4I4l to'identify the No. 0 frame. It may be noted that relays 4I4 to 4I'I represent 'the four frames koi! a choice and are operated from the corresponding energizing circuit for each pair of relays.

With relay 400 operated, the No. 0 line choice is selected by operating the marker preference relay 201, individual to the marker shown, in the No. 0 line choice connector. The marker preference relay operates the multicontact relay 208 which extends all of the control circuits through to the choice. The frame relay 4 I4 closes a circuit from ground through the winding of relay 4|8, contact of relay 4I4 to the winding of relay 209, which is individual to the frame, over equipment (not shown) which determines that the frame equipment is free to handle a terminating call. Relay 4I8 operates if the frame equipment Vis idle and connects ground to the outer left contacts of the level relays 402, 404, etc., and, since relay 402 is assumed to be operated, operates horizontal level relay 2I0. Relay 2I0 connects the operating circuits for the ten select magnets corresponding to the ten line junctors which serve the wanted line through to the marker where one will be selected as described in detail in the above-identied application of Dehn et al. The hold magnet 2II of this line is operated over the front contact of relay 3I4 after an idle channel has .been selected.

If the substation 200 represented the tip party of a two-party line, terminal II3 would be crossconnected to strip I|0 operating relay 400 over conductor 401 and the middle winding of that relay which, in operating, would extend the operating ground to relay 4I9 to control the ringing and charging functions of the marker in accordance therewith.

If the substation 200 represented one of a, group of private branch exchange trunks, terminal |I3 would be cross-connected to strip Il! which is connected to conductor 400. Prior to the closure of the operating circuit for relay 3I4, relays 420 and 42| are operated, connecting ground to conductors 408, 422 and the corresponding operating conductors for each line choice relay. In this case, relay SIG and all similar relays included in the same private branch exchange group are operated so that the ilrst idle trunk of the group may be selected. When an idle trunk has been found and the corresponding relay in the group Relay 400 extends its operatingr the line isone of a group of branch exchange trunks. Y

If, for any reason, it is desired to assign a dinerent number to the line 200, for example that individual to the terminals II4, III and |I0 the jumpers |24, |25 and |28 will be moved to terminals II4, III and IIO. respectively, and n0 other change is necessary.

If, because of trame conditions or other reasons, it is desirable to change the location of a line without changing the number, forexample to the No. 9 level of the No. 2 frame of the No. 9 choice, the talking conductors are disconnected from the switch terminals 203 and 204 and transferred to terminals 2I2 and 2I3 at the desired location. The sleeve jumper |24 is disconnected from terminal III on the number group frame and jumper |21 is connected between terminal III and'sleeve terminal 2I4 of the new primary line switch. The message register is also disconnected from the message register terminal 200 of the first switch and connected to the message register terminal v2|5 kof the new location. Atthe number group frame, jumpers and |20 are also disconnected and terminal II2 is connected-by jumper |20 to strip |29, while terminal II3 isconnected to strip |30. Therefore, the No. 9-line choice relay 40| is operated through its left wind'- ing and frame level relay 405 is operated through its left winding. l

Line choice relay 40| causes the selection of the No. 9 line choice by operating the preference relay 2| 6 of that choice. Relay 405 causes the operation of frame relay 4I6 which selects the No. 2 frame in the choice, while relay 405 selectsthe No. 9 level on that frame.

It is, therefore, apparent that this arrangement provides great flexibility of line arrangement, it being possible to spread busy groups of private branch exchange trunks over all cholces, thereby relieving the load on any one choice.

What is claimed is:

1. In a telephone system, subscribers lines identified bydirectory numbers, automatic switches, controlequipment common to said lines and said switches, a set of. terminals individual to each directory number, a set of terminals individual t0 each line in said switches, means to individualize one of said sets of number terminals with one of said sets of line terminals, means responsive to the registration of a directory number in said control equipment to connect said control equipment with the corresponding set of number terminals, and means in said control equipment responsive to said connection to control the connection of said control equipment with the set of line terminals individualized with said number terminals.

2..In a telephone system, a plurality of lines, a plurality of switches in which said lines appear, control equipment common to said lines and to said switches, sets of terminals individual to the directory numbers, means to individualize said sets of terminals to subscribers lines, means to register the number of a wanted line in said control equipment, means in said control equipment responsive to said registration to seize the corresponding set of terminals, means in said control equipment operated over said set of terminals to record the location of the correspond- .and to said switches, a cron-connecting rack,

means to register the directory number of a line in said control equipment, means responsive to said registration to select a set ot terminals. on said cross-connecting rack individual to said number, means to individualize said set of terminals to a subscribers. means including said set of terminals to transmit to said control equipment infomation characteristic of the nature and location of said line, and means responsive to the transmission of said information to connect said control equipment with the switch in which said line appears.

4. In a telephone system, a plurality of lines, a plurality oi' switches in which said lines appear, said switches being arranged in levels, frames andl choices, control equipment common to said lines and to said switches, a cross-connecting rack. sets oi terminals on said rack individual to directory numbers, means to individualize said sets ci' terminals to subscribers lines, means to register a directory number in said control equipment, means responsive to said registration to connect said control equipment withk the cross-connecting rack and the set of terminais individual to said number, means operated oversaidsotoiterminalstorecordtheidentity" oi' the choice, frame andlevel on which the corresponding line is located, and meansresponsive to said record i'or connecting said control equipment with said choice, frame and level i'or completing the connection with said line.

5. In a telephone system, a plurality oi lines, a plurality of switches in which said lines appear, said switches being arranged in levels, frames and choices, control equipment common to said lines and to said switches, `.a cross-connecting rack. setsy of terminals on said rack individual to directory numbers, means to individualize said sets oi terminals to subscribers lines, terminal strips on said rack for each choice,terminal strips on said rack for each irame level, means to'crossconnect said sets o! terminals with said terminal strips in accordance with the location ot `the line individualized thereto, `means to register a directory number in said control equipment. means responsiveto said resistration to connect said control equipment with the cross-connecting rack and the set oi terminals individual to said number, means operated over said set oi terminals and said terminal strips to record the ,identity of the choice, frame and level on which the corresponding line is located, and means responsive to said record for connecting said control equipment with said choice, frame and level for com pleting the connection with said line.

WARREN W. CARPENTER. LINUS E. KIITREDGE. 

